<!DOCTYPE html>



  


<html class="theme-next muse use-motion" lang="zh-CN">
<head><meta name="generator" content="Hexo 3.8.0">
  <meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<meta name="theme-color" content="#222">









<meta http-equiv="Cache-Control" content="no-transform">
<meta http-equiv="Cache-Control" content="no-siteapp">
















  
  
  <link href="/blogs/lib/fancybox/source/jquery.fancybox.css?v=2.1.5" rel="stylesheet" type="text/css">







<link href="/blogs/lib/font-awesome/css/font-awesome.min.css?v=4.6.2" rel="stylesheet" type="text/css">

<link href="/blogs/css/main.css?v=5.1.3" rel="stylesheet" type="text/css">


  <link rel="apple-touch-icon" sizes="180x180" href="/blogs/images/apple-touch-icon-next.png?v=5.1.3">


  <link rel="icon" type="image/png" sizes="32x32" href="/blogs/images/favicon-32x32-next.png?v=5.1.3">


  <link rel="icon" type="image/png" sizes="16x16" href="/blogs/images/favicon-16x16-next.png?v=5.1.3">


  <link rel="mask-icon" href="/blogs/images/logo.svg?v=5.1.3" color="#222">





  <meta name="keywords" content="汇编,">





  <link rel="alternate" href="/blogs/atom.xml" title="恋恋风辰的个人博客" type="application/atom+xml">






<meta name="description" content="一：变量类型汇编语言变量基本类型如下： sdword ：表示32位整数 dword：表示32位无符号整数 sword：表示16位整数 word：表示16位无符号整数 sbyte：表示8位整数 byte：用于表示字节，大小为8位 变量的表示和定义： C语言中1int num3 = 5； 汇编中1num3 sdword 5； C语言中123char name1；char name2=‘A’； 汇编中：">
<meta name="keywords" content="汇编">
<meta property="og:type" content="article">
<meta property="og:title" content="汇编语言学习笔记(一)">
<meta property="og:url" content="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/index.html">
<meta property="og:site_name" content="恋恋风辰的个人博客">
<meta property="og:description" content="一：变量类型汇编语言变量基本类型如下： sdword ：表示32位整数 dword：表示32位无符号整数 sword：表示16位整数 word：表示16位无符号整数 sbyte：表示8位整数 byte：用于表示字节，大小为8位 变量的表示和定义： C语言中1int num3 = 5； 汇编中1num3 sdword 5； C语言中123char name1；char name2=‘A’； 汇编中：">
<meta property="og:locale" content="zh-CN">
<meta property="og:image" content="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/1.png">
<meta property="og:image" content="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/2.png">
<meta property="og:image" content="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/1.jpg">
<meta property="og:updated_time" content="2020-06-22T09:30:58.700Z">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" content="汇编语言学习笔记(一)">
<meta name="twitter:description" content="一：变量类型汇编语言变量基本类型如下： sdword ：表示32位整数 dword：表示32位无符号整数 sword：表示16位整数 word：表示16位无符号整数 sbyte：表示8位整数 byte：用于表示字节，大小为8位 变量的表示和定义： C语言中1int num3 = 5； 汇编中1num3 sdword 5； C语言中123char name1；char name2=‘A’； 汇编中：">
<meta name="twitter:image" content="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/1.png">



<script type="text/javascript" id="hexo.configurations">
  var NexT = window.NexT || {};
  var CONFIG = {
    root: '/blogs/',
    scheme: 'Muse',
    version: '5.1.3',
    sidebar: {"position":"left","display":"post","offset":12,"b2t":false,"scrollpercent":false,"onmobile":false},
    fancybox: true,
    tabs: true,
    motion: {"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}},
    duoshuo: {
      userId: '0',
      author: 'Author'
    },
    algolia: {
      applicationID: '',
      apiKey: '',
      indexName: '',
      hits: {"per_page":10},
      labels: {"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}
    }
  };
</script>



  <link rel="canonical" href="https://secondtonone1.gitee.io/blogs/2017/08/12/asm1/">





  <title>汇编语言学习笔记(一) | 恋恋风辰的个人博客</title>
  








</head>

<body itemscope="" itemtype="http://schema.org/WebPage" lang="zh-CN">

  
  
    
  

  <div class="container sidebar-position-left page-post-detail">
    <div class="headband"></div>

    <header id="header" class="header" itemscope="" itemtype="http://schema.org/WPHeader">
      <div class="header-inner"><div class="site-brand-wrapper">
  <div class="site-meta ">
    

    <div class="custom-logo-site-title">
      <a href="/blogs/" class="brand" rel="start">
        <span class="logo-line-before"><i></i></span>
        <span class="site-title">恋恋风辰的个人博客</span>
        <span class="logo-line-after"><i></i></span>
      </a>
    </div>
      
        <p class="site-subtitle"></p>
      
  </div>

  <div class="site-nav-toggle">
    <button>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
    </button>
  </div>
</div>

<nav class="site-nav">
  

  
    <ul id="menu" class="menu">
      
        
        <li class="menu-item menu-item-home">
          <a href="/blogs/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-home"></i> <br>
            
            Home
          </a>
        </li>
      
        
        <li class="menu-item menu-item-archives">
          <a href="/blogs/archives/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-archive"></i> <br>
            
            Archives
          </a>
        </li>
      
        
        <li class="menu-item menu-item-categories">
          <a href="/blogs/categories" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-question-circle"></i> <br>
            
            Categories
          </a>
        </li>
      
        
        <li class="menu-item menu-item-tags">
          <a href="/blogs/tags" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-question-circle"></i> <br>
            
            Tags
          </a>
        </li>
      

      
        <li class="menu-item menu-item-search">
          
            <a href="javascript:;" class="popup-trigger">
          
            
              <i class="menu-item-icon fa fa-search fa-fw"></i> <br>
            
            Search
          </a>
        </li>
      
    </ul>
  

  
    <div class="site-search">
      
  <div class="popup search-popup local-search-popup">
  <div class="local-search-header clearfix">
    <span class="search-icon">
      <i class="fa fa-search"></i>
    </span>
    <span class="popup-btn-close">
      <i class="fa fa-times-circle"></i>
    </span>
    <div class="local-search-input-wrapper">
      <input autocomplete="off" placeholder="Searching..." spellcheck="false" type="text" id="local-search-input">
    </div>
  </div>
  <div id="local-search-result"></div>
</div>



    </div>
  
</nav>



 </div>
    </header>

    <main id="main" class="main">
      <div class="main-inner">
        <div class="content-wrap">
          <div id="content" class="content">
            

  <div id="posts" class="posts-expand">
    

  

  
  
  

  <article class="post post-type-normal" itemscope="" itemtype="http://schema.org/Article">
  
  
  
  <div class="post-block">
    <link itemprop="mainEntityOfPage" href="https://secondtonone1.gitee.io/blogs/blogs/2017/08/12/asm1/">

    <span hidden itemprop="author" itemscope="" itemtype="http://schema.org/Person">
      <meta itemprop="name" content="恋恋风辰">
      <meta itemprop="description" content="">
      <meta itemprop="image" content="/blogs/images/avatar.gif">
    </span>

    <span hidden itemprop="publisher" itemscope="" itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="恋恋风辰的个人博客">
    </span>

    
      <header class="post-header">

        
        
          <h1 class="post-title" itemprop="name headline">汇编语言学习笔记(一)</h1>
        

        <div class="post-meta">
          <span class="post-time">
            
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-o"></i>
              </span>
              
                <span class="post-meta-item-text">Posted on</span>
              
              <time title="Post created" itemprop="dateCreated datePublished" datetime="2017-08-12T11:18:46+08:00">
                2017-08-12
              </time>
            

            

            
          </span>

          
            <span class="post-category">
            
              <span class="post-meta-divider">|</span>
            
              <span class="post-meta-item-icon">
                <i class="fa fa-folder-o"></i>
              </span>
              
                <span class="post-meta-item-text">In</span>
              
              
                <span itemprop="about" itemscope="" itemtype="http://schema.org/Thing">
                  <a href="/blogs/categories/binary/" itemprop="url" rel="index">
                    <span itemprop="name">汇编</span>
                  </a>
                </span>

                
                
              
            </span>
          

          
            
          

          
          

          

          

          

        </div>
      </header>
    

    
    
    
    <div class="post-body" itemprop="articleBody">

      
      

      
        <h2 id="一：变量类型"><a href="#一：变量类型" class="headerlink" title="一：变量类型"></a>一：变量类型</h2><p>汇编语言变量基本类型如下：</p>
<p><code>sdword ：表示32位整数</code></p>
<p><code>dword：表示32位无符号整数</code></p>
<p><code>sword：表示16位整数</code></p>
<p><code>word：表示16位无符号整数</code></p>
<p><code>sbyte：表示8位整数</code></p>
<p><code>byte：用于表示字节，大小为8位</code></p>
<p>变量的表示和定义：</p>
<p>C语言中<br><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">int</span> num3 = <span class="number">5</span>；</span><br></pre></td></tr></table></figure></p>
<p>汇编中<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">num3 sdword 5；</span><br></pre></td></tr></table></figure></p>
<p>C语言中<br><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">char</span> name1；</span><br><span class="line"></span><br><span class="line"><span class="keyword">char</span> name2=‘A’；</span><br></pre></td></tr></table></figure></p>
<p>汇编中：<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">name1 byte ？</span><br><span class="line"></span><br><span class="line">name2 byte ‘A’；</span><br></pre></td></tr></table></figure></p>
<p>C语言中：<br><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">char</span> name[] = <span class="string">"iloveu"</span>;</span><br></pre></td></tr></table></figure></p>
<p>汇编中：<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">name byte ‘iloveu’，0 ;字符串结汇通常带有二进制的0，占用一个字节。</span><br></pre></td></tr></table></figure></p>
<a id="more"></a>
<h2 id="二：立即数的存储"><a href="#二：立即数的存储" class="headerlink" title="二：立即数的存储"></a>二：立即数的存储</h2><p><code>在汇编语言中将一个常量存储在内存空间需要通过mov操作，立即数为一个常量</code>。</p>
<p>将5存储在变量num1中</p>
<p>num1 sdword ？;</p>
<p>mov num1 5;</p>
<p><code>mov操作后面两个参数为内存或寄存器，mov两个参数可以为以下关系：</code></p>
<p><code>mov mem , imm 将立即数存储到内存中</code></p>
<p><code>mov reg, mem 将内存单元的数据存储到寄存器中</code></p>
<p><code>mov mem, reg 将寄存器中的内容存储到内存单元中</code></p>
<p><code>mov reg, imm 将立即数存储在寄存器单元中</code></p>
<p><code>mov reg, reg 将第二个寄存器中的内容存储到第一个寄存器中</code></p>
<p><code>但是不能mov mem, mem</code>， 不能将一个内存中的内容存储到另一个内存中</p>
<p>需要通过mov reg， mem1； mov mem2 reg；可达到目的。</p>
<h2 id="三：寄存器"><a href="#三：寄存器" class="headerlink" title="三：寄存器"></a>三：寄存器</h2><p>数据不能直接从一个内存单元中移动到另一个内存单元中，需通过寄存器做中转。</p>
<p><code>内存单元数据放在随机存储器(RAM)中</code>，<code>RAM将内存单元中的数据拷贝到CPU的寄存器中</code>，然后将CPU的寄存器中的数据copy到另一个存储单元中。<br><img src="1.png" alt="1.png"></p>
<p><code>将内存单元的内容复制到寄存器中的动作成为装载</code>，<code>将cpu中寄存器的数据copy到内存中成为存储</code>。</p>
<p>不是所有的寄存器都可以被开发者使用，提供给程序员的寄存器为通用寄存器。</p>
<p><code>16位通用寄存器为ax,bx,cx,dx</code></p>
<p><code>32位通用寄存器为eax,ebx,ecx,edx</code></p>
<p><code>以eax举例，eax低16位为ax寄存器，ax寄存器低8位为al寄存器，高8位为ah寄存器</code>。如图所示：</p>
<p><img src="2.png" alt="2.png"></p>
<p><code>eax为累加器</code>，<code>主要用于参与算术逻辑</code></p>
<p><code>ebx为基址寄存器</code>，<code>用于处理数组</code></p>
<p><code>ecx为计数器</code>，<code>用于循环操作</code></p>
<p><code>edx为数据寄存器</code>，<code>用于算术指令</code>。</p>
<p>除此之外还有<code>eflags表示状态的寄存器，esp堆栈指针指向栈顶部，ebp基址指针指向栈底部</code>。</p>
<h2 id="四：输入输出"><a href="#四：输入输出" class="headerlink" title="四：输入输出"></a>四：输入输出</h2><p>字符串的输出</p>
<p>C语言版：<br><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;stdio.h&gt;</span></span></span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">     <span class="built_in">printf</span>(<span class="string">"%s\n"</span>,<span class="string">" Hello World!"</span>);  </span><br><span class="line">     <span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<p>用汇编实现为：</p>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">            .386</span><br><span class="line">            .model flat ,c</span><br><span class="line">            .stack 100h</span><br><span class="line">printf      PROTO arg1:Ptr Byte, printlist:VARARG</span><br><span class="line">            .data</span><br><span class="line">msg1fmt     byte &quot;%s&quot;, 0Ah, 0</span><br><span class="line">msg1        byte &quot;Hello World&quot;, 0</span><br><span class="line">            .code</span><br><span class="line">main        proc</span><br><span class="line">            INVOKE printf, ADDR msg1fmt, ADDR msg1</span><br><span class="line">            ret</span><br><span class="line">main        endp</span><br><span class="line">            end</span><br></pre></td></tr></table></figure>
<p> <code>.386是一个汇编指令</code>，它指明程序可以被汇编为在Intel386系列或更高级的计算机运行，</p>
<p><code>.model flat表明程序使用保护模式</code>，.model flat ,c表示该程序可以与C或C++程序进行连接，且需要运行在Visual C++环境中。</p>
<p><code>.stack 100h 表示堆栈的大小应该达到十六进制100个字节</code></p>
<p><code>printf 名称后面的 PROTO表示printf为函数原型， arg1表示printf第一个参数为指向Byte类型的Ptr指针。</code></p>
<p>第二个参数为VARARG类型可变参数printlist</p>
<p><code>.data表示数据段，.code表示代码段。</code></p>
<p><code>msg1fmt 为byte类型的字符串,0Ah为16进制表示\n,0表示字符串结尾\0</code></p>
<p><code>msg1为byte类型的字符串，“Hello World”</code></p>
<p><code>proc汇编指令表示一个过程，过程名称为main</code></p>
<p><code>INVOKE 为汇编指令，调用函数printf完成输出，</code></p>
<p><code>格式为 INVOKE 函数名， 参数一，参数二</code></p>
<p>这里为msg1fmt字符串的首地址，以及msg1的首地址。</p>
<p><code>ADDR为取地址操作。</code></p>
<p><code>ret表示返回和C语言return 0一样。</code></p>
<p><code>main endp表示main proc结束</code></p>
<p><code>end表示整个汇编程序结束。</code></p>
<p>整数的输出和字符串类似，下面通过输入输出程序介绍汇编语言的输入和输出</p>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line">　　　　 .386</span><br><span class="line">　　　　 .model flat c</span><br><span class="line">　　　　 .stack 100h</span><br><span class="line">printf  PROTO arg1:Ptr Byte, printlist:VARARG</span><br><span class="line">scanf   PROTO arg2:Ptr Byte, inputlist:VARARG</span><br><span class="line">　　　　 .data</span><br><span class="line">in1fmt  byte &quot;%d&quot;, 0</span><br><span class="line">msg0fmt byte 0Ah, &quot;%s&quot;, 0</span><br><span class="line">msg1fmt byte 0Ah, &quot;%s%d&quot;, 0Ah, 0Ah, 0</span><br><span class="line">msg0    byte &quot;Enter an integer for num1: &quot;, 0</span><br><span class="line">msg1    byte &quot;The integer in num2 is: &quot;,0</span><br><span class="line">num1 　 sdword ?</span><br><span class="line">num2    sdword ?</span><br><span class="line">　　　　.code</span><br><span class="line">main   proc</span><br><span class="line">　　　 INVOKE printf, ADDR msg0fmt, ADDR msg0</span><br><span class="line">       INVOKE scanf, ADDR in1fmt, ADDR num1</span><br><span class="line">       mov eax, num1</span><br><span class="line">       mov num2, eax</span><br><span class="line">       INVOKE printf, ADDR msg1fmt, ADDR msg1, num2</span><br><span class="line">      ret</span><br><span class="line">main  endp</span><br><span class="line">      end</span><br></pre></td></tr></table></figure>
<p>输入和输出类似，C语言中输入函数为scanf</p>
<p>汇编程序通过</p>
<p><code>scanf   PROTO arg2:Ptr Byte, inputlist:VARARG</code><br><code>PROTO表示scanf为函数原型， 第一个参数为指向Byte的指针,第二个参数为可变参数</code><br><code>scanf输入整数num1，需要取地址，所以会采用ADDR num1</code></p>
<p>将上述汇编转译为C语言<br><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;stdio.h&gt;</span></span></span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    <span class="keyword">int</span> num1, num2;</span><br><span class="line">    <span class="built_in">printf</span>(<span class="string">"\n%s"</span>, <span class="string">"Enter an integer for num1: "</span>);</span><br><span class="line">    <span class="built_in">scanf</span>(<span class="string">"%d"</span>, &amp;num1);</span><br><span class="line">    num2 = num1;</span><br><span class="line">    <span class="built_in">printf</span>(<span class="string">"\n%s%d\n\n"</span>, <span class="string">"The integer in num2 is: "</span>, num2);</span><br><span class="line">    <span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line"></span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure></p>
<h2 id="五：算数指令"><a href="#五：算数指令" class="headerlink" title="五：算数指令"></a>五：算数指令</h2><p>加法指令</p>
<p><code>add mem, imm  将立即数imm和内存单元mem中数值相加存储在mem中</code></p>
<p><code>add reg, mem 将内存mem中的数值和寄存器reg中的数值相加，结果存储在reg中</code></p>
<p><code>add reg, imm 将立即数imm和寄存器reg中数据相加存储在reg中</code></p>
<p><code>add mem, reg 将寄存器中的数据和内存单元mem中数据相加存储在mem中</code></p>
<p><code>add reg, reg 将寄存器中的数据和寄存器相加，最后存储在第一个reg中</code></p>
<p>注意：不可add mem, mem 也不可 add imm, imm 两个立即数没法相加结果也没办法存储</p>
<p><code>两个内存单元也没办法相加，和mov mem, mem是一样的，都不可以直接操纵两个内存。</code></p>
<p>减法指令</p>
<p><code>sub mem, imm 将内存单元mem中数据减去立即数imm存储在mem中</code></p>
<p><code>sub reg, mem 将寄存器reg中数据减去mem中的数据，存储在reg中。</code></p>
<p><code>sub mem, reg 将内存单元mem中数据减去寄存器reg中数据，结果存储在mem中</code></p>
<p><code>sub reg ,imm 将寄存器reg中的数据减去立即数imm，将结果存储在reg中</code></p>
<p><code>sub reg, reg 将第一个reg数据减去第二个reg数据，最后结果存储在第一个reg中</code></p>
<p>`注意：不可sub mem, mem 也不可 add imm, imm 两个立即数没法相减结果也没办法存储</p>
<p>两个内存单元也没办法相减，和mov mem, mem是一样的，都不可以直接操纵两个内存。`</p>
<p>乘法指令imul</p>
<p><code>imul mem 将内存单元mem中的数据和寄存器eax中的数据相乘，结果存储在edx:eax中</code></p>
<p><code>imul reg 将寄存器reg中的数据和寄存器eax中的数据相乘，结果存储在edx:eax中</code></p>
<p><code>注意：imul 只有一个参数，这个参数只能为内存单元或者寄存器，不能是imm立即数</code></p>
<p><code>由于乘法指令imul可能会造成乘积位数大于乘数和被乘数的位数，所以将结果存储在edx:eax中</code></p>
<p><code>imul为有符号的乘法指令， mul为无符号的乘法指令， imul和mul参数只能为mem或reg</code>，如果</p>
<p>想计算num = mem* 3；mem为内存单元数据，3为立即数</p>
<p>imul实现为<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">mov eax, 3</span><br><span class="line"></span><br><span class="line">imul mem</span><br><span class="line"></span><br><span class="line">mov num, eax</span><br></pre></td></tr></table></figure></p>
<p><code>除法指令idiv</code></p>
<p><code>和乘法指令类似，idiv 为有符号除法， div为无符号除法</code></p>
<p><code>进行除法操作前将被除数放入edx:eax中，除法操作后edx存储的为余数，eax存储的为商。</code></p>
<p>举例 num = 13/,5;</p>
<p><code>汇编语言实现过程先将13放入eax中，调用cdq 可以将eax内容扩展到edx:eax寄存器对中，将5放入内存单元或寄存器中，调用idiv最终edx存储为3，eax存储为2</code></p>
<p>汇编语言实现如下：<br><figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">mov eax， 13</span><br><span class="line">mov ebx，5</span><br><span class="line">cdq</span><br><span class="line">idiv ebx</span><br><span class="line">mov num , eax</span><br></pre></td></tr></table></figure></p>
<p><code>cbw 指令可将字节转换为字，一个字为两个字节，即将al内容扩展到寄存器ax中</code></p>
<p><code>cwd 字转换为双字， 即将ax中的内容扩展到eax中</code></p>
<p><code>cdq 双字转换为4个字， 即将eax中内容扩充为edx:eax中。</code></p>
<p><code>只有cdq允许有符号位，所以进行idiv和div操作前执行cdq将eax中内容扩充到edx:eax中。</code></p>
<p><code>注意：idiv和div 只有一个参数，这个参数只能为内存单元或者寄存器，不能是imm立即数</code></p>
<p>自增自减指令</p>
<p><code>dec reg</code>    reg中的数据自减</p>
<p><code>dec mem</code>   mem中的数据自减</p>
<p><code>inc reg</code>    reg中数据自增</p>
<p><code>inc mem</code>    mem中数据自增。</p>
<p><code>注意：dec 和inc  只有一个参数，这个参数只能为内存单元或者寄存器，不能是imm立即数</code></p>
<p>取反指令，也就是求一个数的补码</p>
<p><code>neg mem</code></p>
<p><code>neg imm</code></p>
<p><code>注意：neg  只有一个参数，这个参数只能为内存单元或者寄存器，不能是imm立即数</code></p>
<p>下面两个例子是综合计算</p>
<figure class="highlight plain"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">; v = -w + m * 3 - y/(z-4) </span><br><span class="line">;w,v,m,y, z分别为内存单元</span><br><span class="line"></span><br><span class="line">mov ebx, w</span><br><span class="line">neg ebx</span><br><span class="line">mov eax,3</span><br><span class="line">imul m</span><br><span class="line">add eax, ebx</span><br><span class="line">mov v ,eax</span><br><span class="line">mov ebx, z</span><br><span class="line">sub ebx, 4</span><br><span class="line">mov eax, y</span><br><span class="line">cdq</span><br><span class="line">idiv ebx</span><br><span class="line">sub v, eax</span><br></pre></td></tr></table></figure>
<p>汇编语言基础第一部分记录到此为止，下一篇跟进记录</p>
<p><img src="1.jpg" alt="1.jpg"></p>

      
    </div>
    
    
    

    

    

    

    <footer class="post-footer">
      
        <div class="post-tags">
          
            <a href="/blogs/tags/汇编/" rel="tag"># 汇编</a>
          
        </div>
      

      
      
      

      
        <div class="post-nav">
          <div class="post-nav-next post-nav-item">
            
              <a href="/blogs/2017/08/12/asmset/" rel="next" title="win7 64位环境下配置汇编环境和程序设计">
                <i class="fa fa-chevron-left"></i> win7 64位环境下配置汇编环境和程序设计
              </a>
            
          </div>

          <span class="post-nav-divider"></span>

          <div class="post-nav-prev post-nav-item">
            
              <a href="/blogs/2017/08/12/asm2/" rel="prev" title="汇编语言学习笔记(二)">
                汇编语言学习笔记(二) <i class="fa fa-chevron-right"></i>
              </a>
            
          </div>
        </div>
      

      
      
    </footer>
  </div>
  
  
  
  </article>



    <div class="post-spread">
      
    </div>
  </div>


          </div>
          


          

  



        </div>
        
          
  
  <div class="sidebar-toggle">
    <div class="sidebar-toggle-line-wrap">
      <span class="sidebar-toggle-line sidebar-toggle-line-first"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-middle"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-last"></span>
    </div>
  </div>

  <aside id="sidebar" class="sidebar">
    
    <div class="sidebar-inner">

      

      
        <ul class="sidebar-nav motion-element">
          <li class="sidebar-nav-toc sidebar-nav-active" data-target="post-toc-wrap">
            Table of Contents
          </li>
          <li class="sidebar-nav-overview" data-target="site-overview-wrap">
            Overview
          </li>
        </ul>
      

      <section class="site-overview-wrap sidebar-panel">
        <div class="site-overview">
          <div class="site-author motion-element" itemprop="author" itemscope="" itemtype="http://schema.org/Person">
            
              <p class="site-author-name" itemprop="name">恋恋风辰</p>
              <p class="site-description motion-element" itemprop="description">重剑无锋，大巧不工</p>
          </div>

          <nav class="site-state motion-element">

            
              <div class="site-state-item site-state-posts">
              
                <a href="/blogs/archives/">
              
                  <span class="site-state-item-count">146</span>
                  <span class="site-state-item-name">posts</span>
                </a>
              </div>
            

            
              
              
              <div class="site-state-item site-state-categories">
                <a href="/blogs/categories/index.html">
                  <span class="site-state-item-count">11</span>
                  <span class="site-state-item-name">categories</span>
                </a>
              </div>
            

            
              
              
              <div class="site-state-item site-state-tags">
                <a href="/blogs/tags/index.html">
                  <span class="site-state-item-count">15</span>
                  <span class="site-state-item-name">tags</span>
                </a>
              </div>
            

          </nav>

          
            <div class="feed-link motion-element">
              <a href="/blogs/atom.xml" rel="alternate">
                <i class="fa fa-rss"></i>
                RSS
              </a>
            </div>
          

          <div class="links-of-author motion-element">
            
              
                <span class="links-of-author-item">
                  <a href="https://github.com/secondtonone1" target="_blank" title="GitHub">
                    
                      <i class="fa fa-fw fa-github"></i>GitHub</a>
                </span>
              
                <span class="links-of-author-item">
                  <a href="https://www.zhihu.com/people/wang-wu-chen-32/activities" target="_blank" title="ZhiHu">
                    
                      <i class="fa fa-fw fa-ZhiHu"></i>ZhiHu</a>
                </span>
              
            
          </div>

          
          

          
          

          

        </div>
      </section>

      
      <!--noindex-->
        <section class="post-toc-wrap motion-element sidebar-panel sidebar-panel-active">
          <div class="post-toc">

            
              
            

            
              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-2"><a class="nav-link" href="#一：变量类型"><span class="nav-number">1.</span> <span class="nav-text">一：变量类型</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#二：立即数的存储"><span class="nav-number">2.</span> <span class="nav-text">二：立即数的存储</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#三：寄存器"><span class="nav-number">3.</span> <span class="nav-text">三：寄存器</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#四：输入输出"><span class="nav-number">4.</span> <span class="nav-text">四：输入输出</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#五：算数指令"><span class="nav-number">5.</span> <span class="nav-text">五：算数指令</span></a></li></ol></div>
            

          </div>
        </section>
      <!--/noindex-->
      

      

    </div>
  </aside>


        
      </div>
    </main>

    <footer id="footer" class="footer">
      <div class="footer-inner">
        <div class="copyright">&copy; <span itemprop="copyrightYear">2020</span>
  <span class="with-love">
    <i class="fa fa-user"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">恋恋风辰</span>

  
  
 
    <script async src="//busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js"></script>
    <span id="busuanzi_container_site_pv">本站总访问量<span id="busuanzi_value_site_pv"></span>次</span>
    <span class="post-meta-divider">|</span>
    <span id="busuanzi_container_site_uv">本站访客数<span id="busuanzi_value_site_uv"></span>人</span>
 
 
</div>


  <div class="powered-by">Powered by <a class="theme-link" target="_blank" href="https://hexo.io">Hexo</a></div>



  <span class="post-meta-divider">|</span>



  <div class="theme-info">Theme &mdash; <a class="theme-link" target="_blank" href="https://github.com/iissnan/hexo-theme-next">NexT.Muse</a> v5.1.3</div>




        







        
      </div>
    </footer>

    
      <div class="back-to-top">
        <i class="fa fa-arrow-up"></i>
        
      </div>
    

    

  </div>

  

<script type="text/javascript">
  if (Object.prototype.toString.call(window.Promise) !== '[object Function]') {
    window.Promise = null;
  }
</script>









  












  
  
    <script type="text/javascript" src="/blogs/lib/jquery/index.js?v=2.1.3"></script>
  

  
  
    <script type="text/javascript" src="/blogs/lib/fastclick/lib/fastclick.min.js?v=1.0.6"></script>
  

  
  
    <script type="text/javascript" src="/blogs/lib/jquery_lazyload/jquery.lazyload.js?v=1.9.7"></script>
  

  
  
    <script type="text/javascript" src="/blogs/lib/velocity/velocity.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/blogs/lib/velocity/velocity.ui.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/blogs/lib/fancybox/source/jquery.fancybox.pack.js?v=2.1.5"></script>
  


  


  <script type="text/javascript" src="/blogs/js/src/utils.js?v=5.1.3"></script>

  <script type="text/javascript" src="/blogs/js/src/motion.js?v=5.1.3"></script>



  
  

  
  <script type="text/javascript" src="/blogs/js/src/scrollspy.js?v=5.1.3"></script>
<script type="text/javascript" src="/blogs/js/src/post-details.js?v=5.1.3"></script>



  


  <script type="text/javascript" src="/blogs/js/src/bootstrap.js?v=5.1.3"></script>



  


  




	





  





  












  

  <script type="text/javascript">
    // Popup Window;
    var isfetched = false;
    var isXml = true;
    // Search DB path;
    var search_path = "search.xml";
    if (search_path.length === 0) {
      search_path = "search.xml";
    } else if (/json$/i.test(search_path)) {
      isXml = false;
    }
    var path = "/blogs/" + search_path;
    // monitor main search box;

    var onPopupClose = function (e) {
      $('.popup').hide();
      $('#local-search-input').val('');
      $('.search-result-list').remove();
      $('#no-result').remove();
      $(".local-search-pop-overlay").remove();
      $('body').css('overflow', '');
    }

    function proceedsearch() {
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay"></div>')
        .css('overflow', 'hidden');
      $('.search-popup-overlay').click(onPopupClose);
      $('.popup').toggle();
      var $localSearchInput = $('#local-search-input');
      $localSearchInput.attr("autocapitalize", "none");
      $localSearchInput.attr("autocorrect", "off");
      $localSearchInput.focus();
    }

    // search function;
    var searchFunc = function(path, search_id, content_id) {
      'use strict';

      // start loading animation
      $("body")
        .append('<div class="search-popup-overlay local-search-pop-overlay">' +
          '<div id="search-loading-icon">' +
          '<i class="fa fa-spinner fa-pulse fa-5x fa-fw"></i>' +
          '</div>' +
          '</div>')
        .css('overflow', 'hidden');
      $("#search-loading-icon").css('margin', '20% auto 0 auto').css('text-align', 'center');

      $.ajax({
        url: path,
        dataType: isXml ? "xml" : "json",
        async: true,
        success: function(res) {
          // get the contents from search data
          isfetched = true;
          $('.popup').detach().appendTo('.header-inner');
          var datas = isXml ? $("entry", res).map(function() {
            return {
              title: $("title", this).text(),
              content: $("content",this).text(),
              url: $("url" , this).text()
            };
          }).get() : res;
          var input = document.getElementById(search_id);
          var resultContent = document.getElementById(content_id);
          var inputEventFunction = function() {
            var searchText = input.value.trim().toLowerCase();
            var keywords = searchText.split(/[\s\-]+/);
            if (keywords.length > 1) {
              keywords.push(searchText);
            }
            var resultItems = [];
            if (searchText.length > 0) {
              // perform local searching
              datas.forEach(function(data) {
                var isMatch = false;
                var hitCount = 0;
                var searchTextCount = 0;
                var title = data.title.trim();
                var titleInLowerCase = title.toLowerCase();
                var content = data.content.trim().replace(/<[^>]+>/g,"");
                var contentInLowerCase = content.toLowerCase();
                var articleUrl = decodeURIComponent(data.url);
                var indexOfTitle = [];
                var indexOfContent = [];
                // only match articles with not empty titles
                if(title != '') {
                  keywords.forEach(function(keyword) {
                    function getIndexByWord(word, text, caseSensitive) {
                      var wordLen = word.length;
                      if (wordLen === 0) {
                        return [];
                      }
                      var startPosition = 0, position = [], index = [];
                      if (!caseSensitive) {
                        text = text.toLowerCase();
                        word = word.toLowerCase();
                      }
                      while ((position = text.indexOf(word, startPosition)) > -1) {
                        index.push({position: position, word: word});
                        startPosition = position + wordLen;
                      }
                      return index;
                    }

                    indexOfTitle = indexOfTitle.concat(getIndexByWord(keyword, titleInLowerCase, false));
                    indexOfContent = indexOfContent.concat(getIndexByWord(keyword, contentInLowerCase, false));
                  });
                  if (indexOfTitle.length > 0 || indexOfContent.length > 0) {
                    isMatch = true;
                    hitCount = indexOfTitle.length + indexOfContent.length;
                  }
                }

                // show search results

                if (isMatch) {
                  // sort index by position of keyword

                  [indexOfTitle, indexOfContent].forEach(function (index) {
                    index.sort(function (itemLeft, itemRight) {
                      if (itemRight.position !== itemLeft.position) {
                        return itemRight.position - itemLeft.position;
                      } else {
                        return itemLeft.word.length - itemRight.word.length;
                      }
                    });
                  });

                  // merge hits into slices

                  function mergeIntoSlice(text, start, end, index) {
                    var item = index[index.length - 1];
                    var position = item.position;
                    var word = item.word;
                    var hits = [];
                    var searchTextCountInSlice = 0;
                    while (position + word.length <= end && index.length != 0) {
                      if (word === searchText) {
                        searchTextCountInSlice++;
                      }
                      hits.push({position: position, length: word.length});
                      var wordEnd = position + word.length;

                      // move to next position of hit

                      index.pop();
                      while (index.length != 0) {
                        item = index[index.length - 1];
                        position = item.position;
                        word = item.word;
                        if (wordEnd > position) {
                          index.pop();
                        } else {
                          break;
                        }
                      }
                    }
                    searchTextCount += searchTextCountInSlice;
                    return {
                      hits: hits,
                      start: start,
                      end: end,
                      searchTextCount: searchTextCountInSlice
                    };
                  }

                  var slicesOfTitle = [];
                  if (indexOfTitle.length != 0) {
                    slicesOfTitle.push(mergeIntoSlice(title, 0, title.length, indexOfTitle));
                  }

                  var slicesOfContent = [];
                  while (indexOfContent.length != 0) {
                    var item = indexOfContent[indexOfContent.length - 1];
                    var position = item.position;
                    var word = item.word;
                    // cut out 100 characters
                    var start = position - 20;
                    var end = position + 80;
                    if(start < 0){
                      start = 0;
                    }
                    if (end < position + word.length) {
                      end = position + word.length;
                    }
                    if(end > content.length){
                      end = content.length;
                    }
                    slicesOfContent.push(mergeIntoSlice(content, start, end, indexOfContent));
                  }

                  // sort slices in content by search text's count and hits' count

                  slicesOfContent.sort(function (sliceLeft, sliceRight) {
                    if (sliceLeft.searchTextCount !== sliceRight.searchTextCount) {
                      return sliceRight.searchTextCount - sliceLeft.searchTextCount;
                    } else if (sliceLeft.hits.length !== sliceRight.hits.length) {
                      return sliceRight.hits.length - sliceLeft.hits.length;
                    } else {
                      return sliceLeft.start - sliceRight.start;
                    }
                  });

                  // select top N slices in content

                  var upperBound = parseInt('1');
                  if (upperBound >= 0) {
                    slicesOfContent = slicesOfContent.slice(0, upperBound);
                  }

                  // highlight title and content

                  function highlightKeyword(text, slice) {
                    var result = '';
                    var prevEnd = slice.start;
                    slice.hits.forEach(function (hit) {
                      result += text.substring(prevEnd, hit.position);
                      var end = hit.position + hit.length;
                      result += '<b class="search-keyword">' + text.substring(hit.position, end) + '</b>';
                      prevEnd = end;
                    });
                    result += text.substring(prevEnd, slice.end);
                    return result;
                  }

                  var resultItem = '';

                  if (slicesOfTitle.length != 0) {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + highlightKeyword(title, slicesOfTitle[0]) + "</a>";
                  } else {
                    resultItem += "<li><a href='" + articleUrl + "' class='search-result-title'>" + title + "</a>";
                  }

                  slicesOfContent.forEach(function (slice) {
                    resultItem += "<a href='" + articleUrl + "'>" +
                      "<p class=\"search-result\">" + highlightKeyword(content, slice) +
                      "...</p>" + "</a>";
                  });

                  resultItem += "</li>";
                  resultItems.push({
                    item: resultItem,
                    searchTextCount: searchTextCount,
                    hitCount: hitCount,
                    id: resultItems.length
                  });
                }
              })
            };
            if (keywords.length === 1 && keywords[0] === "") {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-search fa-5x" /></div>'
            } else if (resultItems.length === 0) {
              resultContent.innerHTML = '<div id="no-result"><i class="fa fa-frown-o fa-5x" /></div>'
            } else {
              resultItems.sort(function (resultLeft, resultRight) {
                if (resultLeft.searchTextCount !== resultRight.searchTextCount) {
                  return resultRight.searchTextCount - resultLeft.searchTextCount;
                } else if (resultLeft.hitCount !== resultRight.hitCount) {
                  return resultRight.hitCount - resultLeft.hitCount;
                } else {
                  return resultRight.id - resultLeft.id;
                }
              });
              var searchResultList = '<ul class=\"search-result-list\">';
              resultItems.forEach(function (result) {
                searchResultList += result.item;
              })
              searchResultList += "</ul>";
              resultContent.innerHTML = searchResultList;
            }
          }

          if ('auto' === 'auto') {
            input.addEventListener('input', inputEventFunction);
          } else {
            $('.search-icon').click(inputEventFunction);
            input.addEventListener('keypress', function (event) {
              if (event.keyCode === 13) {
                inputEventFunction();
              }
            });
          }

          // remove loading animation
          $(".local-search-pop-overlay").remove();
          $('body').css('overflow', '');

          proceedsearch();
        }
      });
    }

    // handle and trigger popup window;
    $('.popup-trigger').click(function(e) {
      e.stopPropagation();
      if (isfetched === false) {
        searchFunc(path, 'local-search-input', 'local-search-result');
      } else {
        proceedsearch();
      };
    });

    $('.popup-btn-close').click(onPopupClose);
    $('.popup').click(function(e){
      e.stopPropagation();
    });
    $(document).on('keyup', function (event) {
      var shouldDismissSearchPopup = event.which === 27 &&
        $('.search-popup').is(':visible');
      if (shouldDismissSearchPopup) {
        onPopupClose();
      }
    });
  </script>





  

  

  

  
  

  

  

  

</body>
</html>
